1. Field of the Invention
The invention relates to a shielding connector and to a connector with a connection fit-on detecting function.
2. Description of the Related Art
Japanese Patent Application Laid-Open No. 11-219758 discloses a shielding connector that has a female housing and a male housing to be fitted thereon. The female and male housings each have an outer housing and an inner housing that is suspended in the outer housing through a plurality of ribs. The inner housings accommodate terminal fittings connected to the ends of shielding electric wires. A metal shell is fit on the periphery of the rear end of the inner housing and has slits for receiving the ribs. The metal shell is configured to contact the braided wire of the shielding electric wire. The corresponding female and male terminal fittings are connected to each other when the female and male housings have been fit together. At the same time, the projected ends of the female and male metal shells fit on each other and cover the area of the connection between the female and male terminal fittings. Thus, the female and male terminal fittings are shielded electromagnetically.
The inner housing of the above-described shielding connector is suspended in the outer housing by the ribs. Thus, it is necessary to form the slits on the metal shell. However, the slits align when the projected ends of the female and male metal shells are fit together and the metal shells are open at the positions where the slits align. As, a result, the shielding function of the connector deteriorates.
Each metal shell of the above-described connector is formed from a metal plate that is bent into a rectangular or oblong tube. A convexity at one end of the plate is forcibly fit to a concavity at the other end thereof to form the metal shell. A wide metal shell is liable to open at its widthwise center, and the metal shells will not fit smoothly together if the projected end of either shell opens. Additionally, a gap is formed between the metal shells if either shell opens, and the contact pressure of the contact plate interposed therebetween deteriorates. Thus the electrical connection is unstable and the connector has a poor shielding function.
The male shielding connector of JP 11-219758 is shown in FIG. 37 herein. With reference to FIG. 37, the male shielding connector m has an outer housing 1m and an inner housing 3m. A cavity 2m is formed in the inner housing 3m to accommodate a terminal fitting connected to the end of a shielding electric wire. A metal shell 4m is inserted into the outer housing 1m from its rear end (left side in FIG. 37) and is mounted on the periphery of the inner housing 3m. The metal shell 4m is configured for contacting the braided wire of the shielding electric wire.
A locking claw 5m is formed on the outer surface of the metal shell 4m to prevent the metal shell 4m from slipping off the periphery of the inner housing 3m. A lock 6m is formed on the inner peripheral surface of the outer housing 1m opposed to the outer surface of the metal shell 4m and a rib 7m extends to both sides of the lock 6m. The locking claw 5m passes the rib 7m and rides across the lock 6m as the metal shell 4m is inserted into the outer housing 1m and onto the periphery of the inner housing 3m. Thus, the locking claw 5m is locked to the front surface of the lock 6m, and the metal shell 4m is mounted on the periphery of the inner housing 3m without slipping off. The rib 7m at both sides of the lock 6m minimizes the elastic deformation of the locking claw 5m and enhances locking.
The locking construction of the shielding connector of FIG. 37 requires the stepped configuration of locking claw 6m and the rib 7m on the inner peripheral surface of the outer housing 1m. Thus the peripheral wall of the outer housing 1m is thick and hence the connector housing is radially large.
The female shielding connector of Japanese Patent Application Laid-Open No. 11-219758 is shown in FIGS. 38 and 39 herein. With reference to FIGS. 38 and 39 the female shielding connector f has an outer housing 1f and an inner housing 3f. The inner housing 3f is formed with a cavity 2f to accommodate a terminal fitting connected to the end of the shielding electric wire. A metal shell 4f is inserted into the outer housing 1f from its rear side (right side in FIG. 38) and is mounted on the periphery of the inner housing 3f. The metal shell 4f is configured to contact the braided wire of the shielding electric wire.
A lock 5f is formed as a step on the wall 2fA of the upper side of the cavity 2f, and the locking claw 6f is bent from the corresponding surface of the metal shell 4f. The metal shell 4f is inserted into the outer housing 1f from its rear side and is mounted on the periphery of the inner housing 3f. As a result, the locking claw 6f is pressed by the lock 5f and elastically deforms. The locking claw 6f returns to its original state due to its resiliency and is locked to the lock 5f when the metal shell 4f is inserted to the predetermined position. Thus, the metal shell 4f is mounted on the periphery of the inner housing 3f without slipping off.
The lock 5f is formed as a step on the upper wall 2fA of the cavity 2f. Thus, the diameter of the inner housing 3f is large, and the entire connector housing is large in the radial direction.
Japanese Patent Application Laid-Open No. 2002-141145 and FIG. 40 herein show another connector. With reference to FIG. 40, the connector includes a male housing 1a and a female housing 2a that can be fit on the male housing 1a. The female housing 2a defines a flexing space 3a and a locking arm 4a that deforms elastically into the flexing space 3a while the male housing 1a and the female housing 2a are being fitted together. The locking arm 4a returns elastically to its original state and is locked to the male housing 1a when the male and female housings 1a and 2a have been fit together normally for holding the male and female housings 1a and 2a together.
The female housing 2a also has a detector 5a that can move between a wait position (shown with two-dot chain line in FIG. 40) disposed away from the flexing space 3a and a detection position (shown with solid line in FIG. 40) disposed inside the flexing space 3a. The detector 5a can be pressed from the detection position toward the flexing space 3a when the male and female housings 1a and 2a are in a semi-fit-on state. However, the detector 5a strikes the locking arm 4a that has entered the flexing space 3a to prevent or limit the pressing of the detector 5a. The locking arm 4a moves away from the flexing space 3a when the male and female housings 1a and 2a are in a normal fit-on state. As a result, the detector 5a can advance to the detection position to detect the fit-on state of the male and female housings 1a and 2a. 
The male and female housings 1a and 2a may have to be separated from each other for maintenance. For this purpose, a catch 5A at the rear end of the detector 5a can be gripped manually and pulled rearward. As a result, the detector 5a returns to the wait position, while the semi-locking of the housings 1a and 2a is being released. The locking arm 4a then can be deformed elastically to perform an unlocking operation, and the male and female housings 1a and 2a can be separated.
The connector of FIG. 40 has an advantage of permitting the detector 5a to be returned easily to the wait position so that the housings 1a and 2a can be unlocked and separated. However, foreign matter may press the catch 5A accidentally and return the detector 5a to the wait position. Thus, the housings 1a and 2a can be separated unintentionally.
The invention has been made in view of the above-described problems. Accordingly, it is an object of the present invention to allow a metal shell to enhance a shielding function.
It is another object of the invention to improve the locking construction of the metal shell and to thereby make the housing more compact.
A further object of the invention to achieve a smooth fit of the female and male metal shells on each other and to enhance the shielding function of a shielding connector.
It is a further object of the invention to prevent an inadvertent return of a detection member to a wait position.